The pretransplant pulmonary function test plays an important role in the management of noninfectious pulmonary complications after hematopoietic stem cell transplantation (HCT). Although these tests are widely used as standard preoperative assessments in the nontransplant population, common conditions associated with the HCT patient requires that particular attention be given to interpretation of pulmonary function testing (PFT) results, such as comparison of serial pulmonary function tests and evaluation of the diffusion capacity. Although their utility in helping to predict the likelihood of developing post transplant pulmonary complications and mortality is not well established, current data indicate that pretransplant PFTs are important as a reference for the interpretation of post transplant PFTs and for identifying patients at high risk for developing pulmonary complications and/or mortality after HCT. Future studies of pretransplant pulmonary function should consider the advances in HCT, so that pretransplant PFTs will become a useful tool in pretransplant risk assessment and help the transplant oncologist to determine the most appropriate conditioning regimen for a patient with compromised lung function.